Juan and Rachel have the same number of Marbles

Question

Juan and Rachel have the same number of marbles. Rachel gives away 10 marbles and Juan gives away 22 marbles. Rachel then has three times as many marbles as Juan. How many marbles did each of them have at first?

Answer 1

J=R

R-10=3(J-22)

substitute

J-10=3(J-22)

J-10=3J-66

66-10=3J-J

56=2J

J=56/2

J=28

R=28

check: 28-10=3(28-22)

               18=3(6)=18